Age-related reference intervals for lymphocyte subsets in whole blood of healthy individuals

Enumeration of various lymphocyte subsets is used widely in the diagnosis a nd monitoring of various disease states. With the development of flow cytom etric technology and whole blood analysis, methodologies have become more s ensitive. It is therefore important to establish reference intervals in nor mal, healthy individuals using these techniques to give a better indication of the border between health and disease. Since some lymphocyte subpopulat ions are known to change with age, we have enumerated common subsets in hea lthy individuals from all decades of adult life, including nonagenarian sub jects. We report reference intervals for these subsets in each age group, w hich will be of use in diagnosis and disease monitoring, particularly in el derly subjects, the most rapidly expanding group within the population toda y.